Multi-Tech Systems MT2834BR, MT2834BLR File Transfer Protocols, When to Disable Data Compression

Chapter 3 - Configuration

3.6.3File Transfer Protocols

When you upload or download files with your modem, the host computer will ask which file transfer protocol you want to use. Most communications programs allow you to choose a default protocol. Your software’s documentation should list the ones it can use (not all communications programs support all protocols). Zmodem is the default protocol in MultiExpress for Windows, and we recommend it for most transfers. The following is the MEW File Transfer Protocols screen.

Figure 3-5. MEW File Transfer Protocols Screen

3.7When to Disable Data Compression

If your serial port cannot keep up because it has an older UART, you may lose data when using data compression. Also, the speed advantage hardware compression gives you is entirely dependent on how much the data being transmitted can be compressed. If the data is already in compressed form—a .ZIP or a .SIT file, for example—trying to compress it more will actually slow the transmission slightly compared to transmitting the same file with compression disabled. This effect will be most noticeable if your modem negotiates MNP 5 compression with the other modem. V.42bis will not try to further compress a compressed file, but MNP 5 will.

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